using System;
using System.Collections.Generic;
using System.Text;

namespace Common
{
   class Singleton
  {
    private static Singleton instance;

    // Note: Constructor is 'protected' 
    protected Singleton() 
    {
    }

    public static Singleton Instance()
    {
      // Use 'Lazy initialization' 
      if (instance == null)
      {
        instance = new Singleton();
      }

      return instance;
    }
  }
}
